With declining public support, and declining public budgets for government space activities, national space industries are facing difficulties in continuing their traditional R & D-oriented activities. Although it is understood within the space industry that cost reduction is a key for their business through competition between both communication satellite makers and launch service providers, the results of their efforts to date are still far from encouraging other potential customers who are obliged to follow strict business principles even in space.

In this paper, we have selected two commercial activities, tourism and satellite solar power stations, of which the space transportation requirements are realistically predictable in economic terms. Space tourism is considered as part of the tourism industry - a global business which has driven the development of the civilian aerospace industry since WW2, and which seems large enough to continue to support the aerospace industry in the post cold-war era. Even though the scale of space tourism activities may be much smaller than the airline industry, it is assumed that similar operating concepts will be applied to these new services. The business of satellite solar power stations considered here is to build solar power satellites in low equatorial orbits and sell microwave power to ground-based electric utility companies. The upper limit of the costs for the system will be determined by the price competition of other electricity sources.

The cost targets for space tourism and for space solar power are very close to each other, about 10,000 Yen per 1 kg mass of payload to low Earth orbit. Thus the space industry's current efforts to reduce launch costs by 90% are not sufficient to motivate these new industries to develop in space. A specific effort, targetted at achieving this cost level for space transportation is essential for the space industry to become genuinely commercial and so repay the enormous resources it has used to date.